Apple looking into liquid-cooled MacBooks

Apple is looking into the use of liquid coolants to transport heat in its notebook computer designs, a controversial technique it employed briefly on its line of dual processor Power Mac G5s several years ago.

In a 12-page patent request originally filed in May of last year and published for the first time last week, the Mac maker notes that significant increases in the computational performance of electronic devices over the past few years has made it harder to maintain acceptable internal and external operational temperatures in those devices.

"Portable devices, such as laptop computers, cellular telephones, and personal digital assistants have additional design constraints which make it even harder to manage thermal load," the company said.

In particular, Apple noted that size and weight limitations in such devices can make it difficult to achieve desired operational temperatures. For example, in many portable devices the size and weight of metal heat sinks may be prohibitive, while battery life constraints in such devices may limit the available power for active cooling mechanisms, such as fans.

As a potential solution, Apple proposes a system that includes a power source that is coupled to a heat pipe, where the power source includes an integrated circuit.

"This heat pipe may contain a liquid coolant that has a density greater than a first pre-determined value at room temperature," the filing explains. "A pump is coupled to the heat pipe is configured to circulate the liquid coolant through the heat pipe. Furthermore, a heat exchanger coupled to the heat pipe is configured to transfer heat from the heat pipe to an environment external to the computer system."

More specifically, Apple said the the heat pipe could have a solid copper jacket with a hollow interior that includes a liquid coolant such as water, a coolant in an R133 group of coolants, or a coolant in an R134 group of coolants. The coupled pump would then circulate the liquid coolant, facilitating heat transfer from a power source in the computer system to forced-fluid drivers --such as fans -- that would be located at opposite ends of the heat pipe.

The forced-fluid drivers could also circulate a fluid via fluid-flow ports -- such as vents -- that are tapered such that a cross-sectional area decreases as fluid flows from inside of the computer system to outside the computer system.

"For example, the fluid-flow ports may constitute a Venturi tube," the filing explains in more detail. "Note that this decrease in area may give rise to a Bernoulli effect in which a partial vacuum at the output of the fluid-flow ports (and at the input to fluid-flow port) reduces and/or eliminates recirculation of the fluid flows, thereby reducing the temperature inside of the computer system."

Other variations of the invention could include a mechanical pump or an electrostatic pump. Alternatively, the pump could be configured to circulate the liquid coolant using mechanical vibration such as ultrasonic frequencies of a membrane.

A move towards liquid cooling on its notebook lines wouldn't be Apple's first foray into the liquid cooling Mac business. In the spring of 2004, the company introduced the liquid-cooled dual 2.5GHz PowerMac G5.

The cooling systems were developed for Apple by Troy, Mich-based Delphi, also known as Delphi-Harrison -- a former division of General Motors. As such, they resembled miniature automobile radiators and included a pump, radiator, grills, and a power cable [visual diagrams].

Use of the liquid cooling systems were short lived, however, as they were prone to leaks. As the systems aged, coolant would spill out of the pipes, damaging users' property while also frying many of the PowerMac's internal components along the way. In several cases, Apple determined that it was uneconomical for them to repair the systems and instead began replacing them outright on its own dime.

When I right click on the first 2 articles on the AI homepage, I get a Flash menu instead of the New window / New tab menu. But right clicking on the third article displays the correct menu. Why is that?

Copper filled with fluid? Sounds heavy, unless they get rid of the heat sinks all together.

Quote:

Originally Posted by Leppo

As such, I can't say I'm excited to read this news. Laptops get bumped and shaken around a lot more due to their mobility. Any liquid solution they come up with had better be MUCH more reliable.

I think most notebooks use heat pipes, I haven't heard of those failing systematically like the G5 liquid cooling rigs. I don't think that's what is being patented here. One of the claims looks like something similar to a magneto-hydrodynamic pump device, somewhat like the "caterpillar" drive made popularly known in The Hunt For Red October. Basically, apply a magnetic field through a fluid and it pushes fluid to flow, here, in a loop, without the bother of pistons, fans or other solid objects moving. It still uses fins to dissipate heat, most heat pipes have fins attached on the condenser end, though heat pipes are generally not formed into a loop, this is a loop. Still, MHD is not a very efficient way to get fluid to flow. It might be the reason for metalic particles in the fluid in a figure in the patent filing. I'm a little exhausted to really give the story a thoughrough reading.

You would have thought people would realise by now that sometimes, it takes Apple a while to get around to filing patents. In this case, this looks like evidence that Apple worked on liquid cooling for a G5 PowerBook, but it never saw the light of day.

I was one of the unfortunate owners of a liquid-cooled Dualie G5. It died suddenly and without notice in around (perhaps less) two years of use. The only time I didn't have applecare, too.

As such, I can't say I'm excited to read this news. Laptops get bumped and shaken around a lot more due to their mobility. Any liquid solution they come up with had better be MUCH more reliable.

As the article stated, and also noted on xlr8yourmac.com, Apple replaced the leaking G5's on their own dime, regardless of warranty. They even replaced them with new Mac Pro models after the G5 was discontinued.

You would have thought people would realise by now that sometimes, it takes Apple a while to get around to filing patents. In this case, this looks like evidence that Apple worked on liquid cooling for a G5 PowerBook, but it never saw the light of day.

the patent could be a way to hedge your bets - not so specific as to give away any plans - vague enough to cover future potential products - but also as insurance in case something like liquid cooled notebooks becomes necessary. Although I suspect you are right - this might even have been one of the reasons to switch to Intel for chips - to avoid liquid cooling for a notebook.

For the record water has a much higher heat capacitance than air and so is far more effective at moving heat around - it would seem the idea is to use the fluid to get the heat from the small area (CPU chip for instance) where it is generate to another area where it can be more effectively dissipated. In a self contained system the liquid doesn't provide any additional cooling capacity - only the ability to move the heat around to where you can deal with it more effectively.

Also as an FYI - IBM has been using liquid cooling in mainframes for years - and has recently introduced a number of water cooled products - including systems with fluid in components which are in contact with CPUs - in these systems there is external plumbing and the fluid is circulated in such a way that water chillers can be used to remove the heat much much economically that can be done with air chillers that have to deal with entire rooms. Including an add on for racks that is a basically a water filled door which allows the technology to be deployed strategically where it is needed.

Unless the liquid circulates, a solid metal heat pipe works pretty well. Could this be a patent that came out of research reagrding putting a G5 into a notebook?

I think that Apple wants to reduce the TDP in its notebooks rather than use hotter processors and cool them with fancy, expensive liquid cooling systems.

Speed, low heat, inexpensive to make. Pick any two.

I agree that actual liquid circulating around is an engineering nightmare. It's very difficult to implement even in desktop systems.

However, heatpipes are probably the likely avenue for "liquid" cooling. Probably in the next few years we might see a bit more heat pipe applications in laptops. It's not a huge issue, it's used very commonly and is, well, essential, for fast GPUs and motherboards, CPU heatsink-fans, etc. in custom-built "overclocking" desktops.

The challenge with heatpipes in laptops would be it's about thermal "channeling". Because whatever heat that is generated and transfered, even liquid-cooled, that heat has to be removed. Still, by fans. I'll try to elaborate.

In desktop overclocking, heatpipes are used as a way to most rapidly get heat *away* from the highest-performing components like GPU and CPU cores. This heat is then "dumped" by usually fast, noisy fans towards the rear of the desktop casing. Law of thermodynamics or something, all that heat generated still has to exit the desktop or laptop unit somehow.

In laptops, I would imagine that heatpipes or a "heat-channeled membrane" that the logic board sits in is a way of most efficiently transferring all heat to the vents. Particularly, to avoid a lot of heat buildup at the bottom of the laptop, and dedicate the "heat dumping" areas of the laptop to be at appropriate rear or side vents, not close to your family jewels, for example.

IMHO, things could play out in a few ways. Lowering TDP and Intel's continuing work could really mean much greater cooling efficiency. However, if Intel hits a few snags, Apple would need to put in a bit of heatpipes here and there.

I don't know if it affects the LED display in some way, but to me, the huge back part of the screen casing seems like a nice, large-surface area, away from human contact where you could have pores/vents/etc.

A radical idea would be, imagine if heat generated in the main unit would be transferred via heatpipes/ heat-transfer-membranes to a series of "fins", pores, tiny fans embedded in the display. This combined with the traditional rear fans in the main body of the laptop... would be really cool. Heh, pun unintended.

What I don't understand is why no one is trying to rescue that heat with thermo-electric materials? they're working with them on cars for the x-prize...

That is also a f*king great idea. All that waste thermal energy could be recaptured instead of just dumped out of the desktop/laptop.

Macworld 2015 perhaps:

One more thing... Steve opens laptop. Runs applications at 100% of the 16 CPU cores. Unplugs power adaptor. Audience is intrigued.

Steve then removes the main battery. Audience is totally, absolutely blown away in a gigantic explosion of RDF when they see the laptop is still running, still temporarily powered mostly by the heat generation of the components being converted back to usable electricity*.

*Of course, this process may only last 5 to 15 minutes with the use of another, smaller, spare battery/capacitor, etc. But it is an exaggerated demonstration of what *could* be possible. That is, you could have an Apple laptop that runs cool, and also, in normal and high usage of CPU/GPU, the waste heat is converted *back* into electricity and hence, you still need a main battery or power adaptor, but the power draw is much reduced.

Unless the liquid circulates, a solid metal heat pipe works pretty well. Could this be a patent that came out of research reagrding putting a G5 into a notebook?

I think that Apple wants to reduce the TDP in its notebooks rather than use hotter processors and cool them with fancy, expensive liquid cooling systems.

Speed, low heat, inexpensive to make. Pick any two.

There is no such thing as a solid metal heat pipe. For example, a solid pipe isn't a pipe, it's a rod. The whole idea is to move heat by phase change and fluid flow. This allows the heat to flow quickly to a heat sink away from the heat generator. Just a solid chunk of metal doesn't conduct heat very well.

As the article stated, and also noted on xlr8yourmac.com, Apple replaced the leaking G5's on their own dime, regardless of warranty. They even replaced them with new Mac Pro models after the G5 was discontinued.

Indeed. I have known 3 G5 towers that were replaced including my own. My brother's was out of warranty by over 2 years since he didn't buy Applecare and he received a 4-core Harpertown. My friend and I both received 8-core machines even though he had a dual G5 and I had a quad.

There's a fundamental misunderstanding being shown in this thread of what heat pipes really are. They are not filled with liquid. They have just a little bit of liquid inside, less than a fraction of a drop. The interior of the pipe is microgrooved to wick the liquid down to a pad on the CPU. Heat there evaporates it, drying out the pad and drawing more liquid back. The hot vapor passes to the radiator, where it cools and condenses back to liquid.

And liquid cooling isn't as rare as it was back in the days of the G5 or even as rare as lilgto64 writes. You can find lots of liquid cooling systems for PCs. The big reasons they haven't really caught on are that the aftermarket liquid cooling systems cost a lot more than CPU fan coolers, need some tech knowledge and time to set up, and aren't maintenance-free. But I haven't read about a lot of failures in those systems or motherboards being fried by leaking fluid.

Apostrophes are simple - they are used to indicate either missing letters or possession. Missing letters take precedence. So:
it's = it is / it has, its = belonging to it.
Non-possessive plurals don't have apostrophes.

NO NO NO. I'm calling Bulls--t on you.

Half the world buys into this nonsense.

According to your own definition your second statement contradicts your first statement. There is either a blanket policy for apostrophes or there is NOT.

Apostrophes are for showing possession.

John's = belonging to John. Steves = more than one Steve.

It's = belonging to it, its = it is, it has, it will, or more than one it.

Stop this madness at once, I say, or I will bench you next inning, so help me God.

It's = belonging to it, its = it is, it has, it will, or more than one it.

Stop this madness at once, I say, or I will bench you next inning, so help me God.

Sorry dude, but you are totally wrong. There's not enough room to explain it in my signature, but originally, the apostrophe was for indicating missing letters, and that was it.

Most possessives (aka genitive noun case) used to be formed by adding "es" on to the end of a word. Over time, people started to leave out the "e", putting in an apostrophe to indicate the missing letter. This continued until no-one used "es" any more and it became a "rule" that apostrophes indicate possession.

The genitive of "it" has always been "its", therefore no apostrophe.

Quote:

Originally Posted by echosonic

According to your own definition your second statement contradicts your first statement.

Sorry dude, but you are totally wrong. There's not enough room to explain it in my signature, but originally, the apostrophe was for indicating missing letters, and that was it.

Most possessives (aka genitive noun case) used to be formed by adding "es" on to the end of a word. Over time, people started to leave out the "e", putting in an apostrophe to indicate the missing letter. This continued until no-one used "es" any more and it became a "rule" that apostrophes indicate possession.

The genitive of "it" has always been "its", therefore no apostrophe.

That's a nice history lesson, but languages do evolve, and "it's" meaning "belonging to it" is more consistent than the grammatical way.

IMO the only reason that this hasn't become acceptable yet, is that it makes the current proper usage wrong.

Most language evolution involves a new form that is at first considered a novelty and a mistake, later gaining popularity, finally becoming acceptable, while the old form is at first preferred, later old-fashioned, then obscure and finally historical. Consider why and wherefore.

With "its" and "it's" you can't have a transition, because if "it's" is redefined as "belonging to it" and its is redefined as "it is", the old usage is instantly wrong, and that can't be allowed.

Unfortunately, as a natural language (no "academy" like the French have), English does not tend to move in the direction of more consistency.

Sorry dude, but you are totally wrong. There's not enough room to explain it in my signature, but originally, the apostrophe was for indicating missing letters, and that was it.

Most possessives (aka genitive noun case) used to be formed by adding "es" on to the end of a word. Over time, people started to leave out the "e", putting in an apostrophe to indicate the missing letter. This continued until no-one used "es" any more and it became a "rule" that apostrophes indicate possession.

The genitive of "it" has always been "its", therefore no apostrophe.

Mr. H is entirely correct.

Journalism is publishing what someone doesn't want us to know; the rest is propaganda.-Horacio Verbitsky (el perro), journalist (b. 1942)

That's a nice history lesson, but languages do evolve, and "it's" meaning "belonging to it" is more consistent than the grammatical way.

IMO the only reason that this hasn't become acceptable yet, is that it makes the current proper usage wrong.

Most language evolution involves a new form that is at first considered a novelty and a mistake, later gaining popularity, finally becoming acceptable, while the old form is at first preferred, later old-fashioned, then obscure and finally historical. Consider why and wherefore.

With "its" and "it's" you can't have a transition, because if "it's" is redefined as "belonging to it" and its is redefined as "it is", the old usage is instantly wrong, and that can't be allowed.

Unfortunately, as a natural language (no "academy" like the French have), English does not tend to move in the direction of more consistency.

Indeed. I don't have a problem with language evolving as long as that evolution doesn't make the language worse. In this case, no-one ever uses "its" to mean "it is", people just use "it's" all the time, whether they mean "it is", "it has" or "belonging to it". Granted, most of the time you can work out what was meant, but sometimes it can lead to confusion which would be avoided if the correct word were employed.

The key is the process, by going two-phase you increase the thermal transfer by a factor of at least 6x over single phase water. Also R134a is a dielectric so if it should leak there's no damage to the electronics, a thermal problem to be sure but the system is safe.

The problem with this patents is that it's already being done by Thermal Form & Function out of Boston. Another attempt by Apple to patents someone else's patented process and fight the battle in court. The patent office should NOT allow this to go through.

It's = belonging to it, its = it is, it has, it will, or more than one it.

.

You are wrong, my aspiring writer of English. My English grammar teacher memorably used to say, "The possessive of 'its' doesn't possess one," (an apostrophe).

If you look up 'its' in the dictionary that Apple gives you, it says:

Its is the possessive form of: it ( | the dog licked its paw), while its is the contraction of | it is ( | look, its a dog licking its paw) or | it has ( | Its been too long). The apostrophe in its never denotes a possessive. The confusion is at least partly understandable since other possessive forms (singular nouns) do take an apostrophe + s, as in | the girl's bike or | the president's smile.

Why is it "the Mac maker" rather than "the Cupertino-based Mac maker" ?

It's more poetic:

We are the Mac makers,
And we are the dreamers of dreams,
Wandering by lone sea-breakers,
And sitting by desolate streams;—
World-losers and world-forsakers,
On whom the pale moon gleams:
Yet we are the movers and shakers
Of the world for ever, it seems.

Cupertino-based Mac maker doesn't quite fit.

Quote:

Originally Posted by iCarbon

What I don't understand is why no one is trying to rescue that heat with thermo-electric materials?

I think that's a good idea and it works with Apple's desire to pander to green-peace image. It's a sensible way to improve battery life and should help keep the laptop cooler.

There's clearly technical limitations to overcome though or they would have done it. Lack of room is one issue. Perhaps they could reduce the battery size and the heat conversion would make up for the reduction. Get rid if the optical drive and there's no problem. You could probably fit the entire contents of the power supply brick in that space. It would sure make replacing those magsafes with dodgy plugs a lot more cost-effective.

I like the idea of liquid cooling. This is how our refrigerators work every day without leaking. The cooler the better so whatever techniques can be used are worth experimenting with. The conversion methods have the added benefit of helping the laptop run for longer though.

What they need to start making is waterproof circuitry so the whole thing can be submerged in water. It has the added benefit of making computers safe from accidental spillages.

Somewhat back on topic... I've always heard that liquid cooling is somehow noisier than regular heat sinks and whatnot.

Can someone confirm or deny this?

Hmm, let me see... if the liquid is completely boiled and you get a hole in the heat pipe, then yes, the poor laptopt will sound like a locomotive. Well, joking aside, I don't really know if it is true or not.

it would seem like a great way to decrease heat and increase battery life at the same time

The question here is which is the rate of the energy conversion process. In principle it is very small, so with the amounts of heat you are going to see in a notebook, it makes probably little sense to implement.